half-title page, prepared by publisher

blank page

full title page, prepared by publisher

copyright page, prepared by publisher

Dedication

A Dedication is a section at the very beginning of a book containing a tribute to someone in connection with the writing or publication of the Book.

v

vi Dedication

Preface

A preface is a brief description of a book written by the author of the book. An introductory essay written by a different person is a foreword and precedes an author's preface. The preface often closes with acknowledgements of those who assisted in the project.

A preface generally covers the story of how the book came into being, or how the idea for the book was developed; this is often followed by thanks and acknowledgments to people who were helpful to the author during the time of writing. The preface should be concise, stretching not more than two pages.

Author's Name

vii

viii Preface

Contents

Dedication............................................................................................................................vPreface...............................................................................................................................viiList of Tables......................................................................................................................xiList of Figures....................................................................................................................xiiPart 1....................................................................................................................................1Guidelines for Book Preparation in MS Word using WSPC Style......................................1Chapter 1..............................................................................................................................3Typesetting a Book in MS Word Using the WSPC Book Style..........................................3

1.1 Introduction...............................................................................................................31.2 Using the Template...................................................................................................3

1.2.1 Applying WSPC styles to the document........................................................41.3 Combined TOC and Index using RD Fields.............................................................41.4 Macros.......................................................................................................................51.5 Body text...................................................................................................................6

1.5.1 Parts...............................................................................................................61.5.2 Chapters.........................................................................................................6

1.6 Major Headings.........................................................................................................61.6.1 Sub-headings..................................................................................................6

1.7 Page Numbering the Chapters...................................................................................71.8 Changing the Page Headers......................................................................................71.9 Lists...........................................................................................................................7

1.9.1 Bulleted items................................................................................................71.9.2 Numbered items.............................................................................................8

1.10 Equations.................................................................................................................81.11 Tables......................................................................................................................81.12 Figures.....................................................................................................................91.13 Math Environments...............................................................................................101.14 Quote.....................................................................................................................111.15 Boxes.....................................................................................................................111.16 Appendices............................................................................................................11

Contents

1.17 References and Citations.......................................................................................111.17.1 Unnumbered references.............................................................................11

1.18 Numbered references............................................................................................121.19 RD fields and Indexing.........................................................................................13

Appendix A........................................................................................................................15Sample Appendix...............................................................................................................15

A.1 Sample Appendix Section......................................................................................15A.1.1 Sample Appendix Sub-section....................................................................15

Bibliography......................................................................................................................17Index..................................................................................................................................19

List of Tables

Table 1.1. Single lined table captions are centered to the table width. Long captions are justified to the table width manually............................................9

List of Figures

Fig. 1.1. By default, figure captions are justified to the text width. Center this text if caption does not run for more than one line........................................................10

Fig. 1.1. Chemical structures and abbreviations of the most common cations and anions cited in the chapter.

Fig. 1.2. (a) 81Br NMR spectrum of the neat [C10C1Im][Br] upon increasing temperature and increasing dilution in water (Reprinted with permission from Balevicius et al. 2010. Copyright (2010) American Chemical Society), (b) 129Xe spectra of xenon dissolved in [C4C1Im]+

based ILs (Reprinted with permission from Castiglione et al. 2013. Copyright (2013) American Chemical Society).

Fig. 1.3. (a) Build-up curves from {15N-1H} spectra at several mixing times for AA-TEA and Tf2N-TEA. (b) {13C-1H} HOESY NMR spectrum of AA-TEA and HOE build-up curves. (Both reprinted with permission from Judeinstein et al. 2008. Copyright (2008) American Chemical Society).

Fig. 1.4. Plots of the 14N relaxation rates as a function of temperature for different tetra-alkyl acyclic ammonium-based ILs (Reprinted with permission from Alam et al. 2011. Copyright (2011) American Chemical Society).

1. Introduction

Liquid state NMR is a powerful characterization technique to study chemical structures, intramolecular local motions, translational and rotational dynamic of the whole molecule, solvation and intermolecular interactions [Bagno et al., 2005]. In this chapter we present a summary of the recent work published in the last eight years (2008-2015) on NMR investigation of ionic liquid (IL) systems, with particular emphasis on the structure and dynamics of this class of compounds. Some review papers that also cover the topics included here exist, and should be consulted to get a wider overview of the research field [Rollet and Bessada, 2013; Weingärtner, 2013; Bankmann and Giernoth, 2007]. This chapter is organized as follows. Section 2 gives general remarks on the ionic liquid chemical structure. Section 3 concerns the NMR techniques applied for structure determination. Section 4 deals with molecular dynamics focusing in particular on translational motion (section 4.1) of pure IL as well as solutes dissolved in IL media. Rotational motions are discussed separately in section 4.2.

2. Ionic Liquids

Ionic liquids are composed of scarcely symmetric and very often conformationally flexible ions interacting in a complex and sophisticated collection of ways, including coulombic, dispersive and hydrogen bonds interactions [Weingärtner, 2008]. The balance between the attractive interactions of the opposite charged components and the “packing frustration” due to the steric hindrance and lack of symmetry leads generally to liquid systems at room temperature or, as commonly accepted, at T below 100 °C. The physical chemistry driving these systems to such phase behavior has been exhaustively covered by several authors and largely reviewed in comprehensive reports [Holbrey and Rogers, 2008; Hallet and Welton, 2011]. The majority of ILs are aprotic liquids in which the cations are generally organic molecular ions and the anions can be ether organic or inorganic. Task specific ILs (TSIL) are

Contents

specifically designed to targeted applications by chemical functionalization of one of the alkyl chain, thus making the number and the applications of ILs even broader [Giernoth, 2010]. Finally, a special class of ILs is represented by protic IL (PILS) where the iconicity of the positive and negative components is generated via proton transfer from a Brønsted acid to a pure Brønsted base [Greaves and Drummond, 2008]. The chemical structures of the most representative cations and anions discussed in this chapter are depicted in Figure 1.1.

3. IL structure by NMR

Several high-resolution NMR techniques have recently been applied to determine the structure and dynamics of ionic liquids in the liquid state together with conventional solid-state NMR used for studies in solid samples [Bohmer et al. 2007]. In this chapter we deal with high-resolution liquid state NMR. The solution-state NMR parameters considered are the chemical shift (), indicating the variation in the chemical environment experienced by the observed nucleus, the NMR line width and, whenever available, the quadrupolar constant (CQ), in those cases of nuclei with magnetic quantum number I > ½. Additionally, 2D-NMR techniques based on the Nuclear Overhauser effect (NOE) afford information on the spatial relationship between nuclei.

3.1 Chemical shiftsA great variety of resonant nuclei has been used to study the ILs’ structure and solvation interactions, in correspondence to the presence of various heteroatoms in several ILs components. The next paragraphs provide a brief overview of the applications of multinuclear NMR spectroscopy. 11B-NMR (I=3/2) 11B NMR signals of [C1C4Im][BF4] in organic solvents and in microemulsion were investigated by Falcone et al. [2011] Strong variation in 11B chemical shift and line width resonances was attributed to the formation of layered structure.

15N-NMR (I=1/2) 15N chemical shift [Lycka et al., 2006] of the imidazolium ring for a series of dialkylimidazolium cations were

Bibliography

measured for neat and diluted IL to study the effects of nitrogen atoms substitution, type of anions and influence of solvents used for dilution. The authors found that alkyl substitution influences 15N chemical shifts much more than the effect of anions. Moreover, Burrell et al. [2010] used 15N chemical shift of neat protic ionic liquids (PILs) to study the proton transfer from acid to amine at several acid concentrations. A multinuclear approach was used by Marekha et al. [2015]. 1H, 13C, 15N and 17O chemical shift variations were used to study [C4C1Im][Ac]/water mixtures over the whole mole fraction range. The authors found that when water is added to the IL, the interactions between cation–anion are weakened in favor of those between water and anion.17O-NMR (I=5/2) The work of Bogle et al. [2013] describes an important application of 17O chemical shifts to understand lithium-ion solvation and transport in electrolyte solutions. Several mixtures of ethylene carbonate (EC), dimethyl carbonate (DMC) and 1M LiPF6 have been studied as model systems. The lithium salt produces the largest changes in 17O chemical shift of the EC carbonyl, establishing that Li+

strongly interacts with EC over DMC in nonaqueous electrolyte solutions. Moreover, water 17O chemical shifts were used [Joshi and Pasilis, 2015] to study the hydrogen bonding interactions of tributylphosphate (TBP) and tributylphosphine oxide (TBPO) with the IL [C2C1Im][Tf2N]) in the presence of water. The largest 17O chemical shift variations are induced by the TBPO molecule indicating strong hydrogen bonding interactions with water in the IL system.35Cl-NMR (I=3/2) 35/37Cl chemical shift perturbations together with MD simulations were used by Remsing et al. [2008] to explain the solvation and aggregation process of the [C1C4Im][Cl] IL in water and dimethylsulfoxide at several solvents concentration. 81Br-NMR (I=3/2) 81Br spectra of the neat IL ([C1C10Im][Br]) as well as its solutions in several organic solvents has been investigated [Balevicius et al., 2010]. The complex shape of 81Br NMR signal is attributed to the presence of supra-molecular structures such as mesoscopic domains. The spectra are reported in Figure 1.2 (a). Recently, Endo et al. [2015] reported a comprehensive 81Br NMR study including structure and dynamics of two ILs with bromide anion (see section 4.2).

Contents

89Y-NMR (I=1/2) Nockemann et al. [2009] used 89Y to study the dissolution process of rare earth metal complexes in task-specific ionic liquids (betainium bis(trifluoromethylsulfonyl)imide). 129Xe-NMR (I=1/2) Xenon gas dissolved in imidazolium-based IL [CnCmIm][X]) (with X a broad variety of anions) has been used as a probe of the IL cage structure [Castiglione et al., 2013]. Indeed, 129Xe chemical shift variations (Figure 1.2 (b)) correlate well with the IL structure organization imposed by the anions and with the size of the empty voids due to the charge alternation pattern. The interpretation of the results in terms of sensitivity of 129Xe chemical shift to the compression effects of the dynamic solvent cage were supported by theoretical calculations for xenon dissolved in [C1C4Im][Cl] and [C1C4Im][PF6] [Saielli et al., 2014]. Morgado et al. [2013] studied the effect the alkyl chain length on 129Xe chemical shift in several 1-alkyl-3-methyl-imidazolium cations combined with the anions Cl, PF6, and Tf2N.1H and 13C-NMR (I=1/2) The monitoring of the 1H and 13C NMR chemical shift variation as a function of the gradual changes in the solution composition has become a common method to assess intermolecular interactions in ILs and in their mixtures. The lack of a common internal chemical shift reference like for molecular liquids prompted for calculations of chemical shift. Theoretical calculation of 1H and 13C NMR spectra were performed for the first time by Bagno et al. [2006] for two IL, [C4C1Im][CH3SO4] and [C4C1Im][BF4]. Subsequently, Chen et al. [2013] reported extensive ab initio calculations of the proton chemical shifts for the 1-alkyl-3-methyl-imidazolium cation combined with several anions. Cremer et al. [2010] studied the influence of the anion on the 13C and 1H NMR spectra of eight pure ILs [C1C8Im][X]. The authors correlated the 1H chemical shift with the strength of cation-anion hydrogen bonding. A weak protons shielding corresponds to strong H-bonding.Solvation interactions between imidazolium-based IL and polar molecular solvents or macromolecules have been studied over a wide range of concentrations. Among the most remarkable investigations on the influence of IL imidazolium cation alkyl chain length and/or nature of the anion it is worth mentioning the studies on [CnC1Im][BF4]/[CnC1Im][PF6] in thiophene [Su et al., 2004], [CnC1Im][PF6] in Ac-

Bibliography

d6 [Zhai et al., 2006], [C4C1Im][Tf2N] in acetonitrile (AN), MeOH, DMSO [Takamuku et al., 2014]. Shimomura et al. [2011] demonstrated the formation of IL-benzene clusters in the polar domains for the ILs [CnC1Im][Tf2N] (n=4,12) in benzene solutions independently on the alkyl chain length. Mixtures of four ILs ([C4C1Im][X], X=BF4, PF6, TfO, and Tf2N) with AN were studied over the entire range of concentrations. Marekha and co-workers [2015] have found that hydrogen bonds between the imidazolium ring hydrogen atoms and electronegative atoms of anions are stronger in [C4C1Im][BF4] and [C4C1Im][TfO] and are disrupted upon dilution in AN. Ruiz et al. [2013] provided experimental evidence of the role of hydrogen bonding on the properties of IL−acetone systems. Similarly 1H NMR were used to probe the properties of [C2C1Im][OAc] mixed with seven solvents [Chen et al., 2014], including DMSO [Radhi et al., 2015]. In contrast to organic solvents, specific solvent-solute interactions were observed for macromolecules containing peptides (with L-alanine and L-valine amino acids) [Seitkalieva et al., 2014], proteins [Weingärtner et al., 2012] and cellulose [Kuroda et al., 2014; Gericke et al., 2012] dissolved in IL media. Araujo et al. [2012] studied the dissolution mechanism of several nucleobases in dialkylimidazolium acetate ILs. The authors found significant 13C and 1H shift variation indicating that both ions participate in hydrogen bond formation during the solvation process. 1H NOESY experiments and DFT calculations provided additional evidence concerning the cation−uracil interaction sites. The nature of the solute–solvent interactions for different ILs with ethylene glycol [Singh et al., 2008], and ethylene glycol monomethyl ether (EGMME) [Pal et al., 2011], have been investigated by proton NMR. 1H chemical shifts and their deviations from ideality show multiple hydrogen-bonding interactions of varying strengths between ILs and the alkoxyalkanols molecules in their binary mixtures.

3.3 Magnetization transfer NOEThe nuclear Overhauser effect (NOE) is originated by the cross-relaxation between two interacting nuclei I and S close in space. The magnetization transfer between the interacting nuclei occurs through dipolar mechanisms and is sensitive to molecular motion and to the

Contents

distance r between interacting nuclei. This key point makes the detection and the analysis of NOEs one of the most powerful tool for the assessment of the molecular structure (intramolecular NOE) [Neuhaus and Williamson, 2000] and intermolecular interactions [Brand et al, 2006]. In the case of ILs, the intermolecular NOE data can be exploited for the assessment of the charge alternation pattern and for the study of the local domains. [Mele, 2010]. Gabl, Weingärtner, and Steinhauser [2013] have shown that, for neat ILs, the distance dependence of the intermolecular NOE signal between interacting spins (e.g. 1H belonging to cation and 19F belonging to the anion) may vary between r−6 and r−1

depending on the difference in the Larmor frequencies ωI and ωS of the

two interacting spins. As consequence long range interactions, i.e. aggregation motives extending beyond the first solvation shell, can be detected when the difference between ωI

and ωS is very small, as in the case of proton and fluorine. Conversely, short range interactions dominate the NOEs intensities in the case of proton-lithium [Castiglione et al., 2015].{1H-1H}, {19F-19F} NOESY experiments correlates protons or fluorine via their homonuclear NOE interactions; whereas the {1H-X} HOESY correlates protons with X nuclei (X=7Li, 13C, 15N, 19F, etc.) via heteronuclear interactions. As remarked in section 2, many ILs are composed of cations containing H atoms in an organic frame (e.g. imidazolium, pyridinium, ammonium, pyrrolidinium, etc), and anions that very often do contain F atoms instead of H atoms, typically sulfonylimide-based anions. In such cases, the homonuclear NOE or (rotating frame) ROE provide details on the cation-cation and anion-anion organization, while the heteronuclear {1H-19F}, {1H-7Li}, HOESY measurements spot on the cation-anion and cation-lithium interactions for Li-doped mixtures. Homonuclear NOE The solute-solvent interactions and the site-site distances between toluene and ionic liquids (ILs) [C4C1C1Im][Tf2N] and [C4C1Im][Tf2N] at various molar ratios were determined by intermolecular ROESY experiments and by molecular simulation [Gutel et al., 2009]. Zhao et al. [2008] investigated the microscopic aggregation structure of IL/D2O mixtures [CnC1Im][Br]/D2O (n =6, 8, 10) using 2D NOESY. Similar results were obtained by Marincola et al. [2012].

Bibliography

Remarkable application of rotating frame NOE (ROE) have been reported by Puttik et al. [2011] by using the radical polymerization of methyl metacrylate (MMA) as model system to explore the confinement of the solutes within the domains of the ionic liquid structure.Heteronuclear NOE The cation-interactions between the IL [C12C1Im][Tf2N], and two aryl solvents toluene and trifluorotoluene (TFT) have been clarified by Shimomura et al. [2013] using both homonuclear and heteronuclear NOEs. Intermolecular interactions between a Ru2+(bpy)3

solute and the IL anions and cations of four different systems have been investigated by 2D NOE techniques [Khatun and Castner, 2015]. Lingscheid et al. [2012] investigated the cation-anion interactions in the ILs [C2C1Im][BF4], [C4C1Im][BF4] and [C2C1Im][PF6] by measuring the HOESY spectra both in the neat IL and in solutions of CD2Cl2 and d6-DMSO. They observed that, for the two ILs with the [C4C1Im]+ cation, the more acidic proton at the 2-position of the imidazolium ring showed the strongest interactions with the 19F atoms of the anion. By using {1H−19F} HOESY spectra, Lee et al. [2013] showed that the cation interactions with the [Tf2N]- anions were quite different for cations containing octyl chains relative to homologous cations having isoelectronic ethoxy(ethoxyethyl) chains on the quaternary ammonium or phosphonium cation. Conversely, for piperidinium-based IL (such as [C4C1pip][Tf2N]), the HOESY spectrum showed that the fluorine atoms of Tf2N interacts with all proton of the cation. Combined HOESY and NOESY indicate that [Tf2N]- anion is distributed heterogeneously in the solution [Tripathi and Saha, 2014]. Castiglione et al. [2010, 2011, 2014] have focused on pyrrolidinium based ILs, [C4C1pyr][Tf2N], [C4C1pyr][Pf2N] and [C4C1pyr] [IM14], and their mixtures. Moreover, the effect of lithium-doping on the IL structure have been investigated by {1H−7Li} HOESY. The authors found that that Li+ ions have short contacts with pyrrolidinium cation despite the presence of a positive charge on both species. These results suggest a strong coordination of lithium with the anions giving rise to negatively charged complexes, such as [Li(X)2]− (X = Tf2N, Pf2N, IM14). The kinetics of NOE build-up was studied by performing an array of HOESY experiments at different mixing time for the magnetization transfer in order to obtain detailed quantitative information on the cation-anion [Lingscheid et al., 2012] or lithium-

Contents

cation [Castiglione et al., 2015] distance. {1H-X} HOESY (X= 13C, 15N) also provided useful information on ion association as illustrated by the work of Judeinstein et al. [2008] who recorded 2D HOESY spectra (Figure 1.3 (a), (b)) for several proton conducting ammonium ILs.

4. IL dynamics by NMR

Solution-state NMR affords information on molecular motions for liquids or mobile species for which the NMR spectral lines are sharp enough to measure individual peaks. The molecular dynamics can be investigated either by the analysis of spin-lattice (T1) and spin-spin (T2) relaxation data, which provide information on the rotational and translational motions, or by pulsed field gradient spin-echo (PGSE) NMR measurements. Individual magnetic active nuclei such as 1H, 13C, and 31P for the cation, 19F, 11B for the anion, and 7Li for lithium-doped ILs can be independently observed.

4.1 Translational motionUsing the PGSE methods, the translational diffusion (D) of the individual ions is measured by evaluating the attenuation of the experimental spin-echo signal intensity as a function of the experimental settings. The diffusivity of several class of ILs have been extensively reported over the past twenty years [Rollet and Bessada, 2013]. In most of the papers, the cation and anion diffusion coefficient (Dcation, Danion) were independently measured as a function of the temperature and the experimental data are fitted by an Arrhenius-type linear relation or by the Vogel-Fulcher-Tamman (VFT) equation. Usually, 1H or 31P PGSE NMR accounts for the cation diffusion while 19F nucleus is used to investigate the anions mobility. A recent publication by Herriot et al. [2012] demonstrated that also 13C nuclei at natural abundance are a good probe of both cation and anion diffusion coefficient.Recent studies are focused on the dynamic of Li+ ions in IL doped with lithium salt [Li][X] (with X being the IL anion). In all the investigated mixtures, such as [C3C1pyr][Tf2N] [Hayamizu et al., 2010], [C2C1Im][Tf2N] [Hayamizu et al., 2011; Borodin et al., 2010], [C2C1Im][FSI] [Tsuzuki et al., 2010], [DEME][Tf2N] [Hayamizu et al., 2008], the

Bibliography

presence of lithium introduces an important decrease in viscosity and ions mobility. Moreover, 7Li PGSE NMR studies showed that the Li+

diffusion was always the slowest among the component ions of the binary systems. The observed trend is Dcation > Danion > DLi+. The activation energy for Li+ motion is significantly larger than those of cation and anion in [C4C1pyr][Tf2N] [Castiglione et al., 2011, 2014]. Umecky et al. [2009] measured the ionic mobility of several pure and lithium doped IL mixtures by applying electric field gradient during the PGSE NMR technique. The ions are influenced by the applied field leading to a higher mobility. Sangoro et al. [2011] related broadband dielectric spectroscopy to PFG NMR results to determine the mean ion jump length (about 0.25 nm).

4.1.1 PILS Proton conducting ionic liquids form another class of IL well suited for applications involving the availability of an acidic proton, such as proton exchange membrane fuel cell [Mustarelli, 2010]. Several studies on the diffusion mechanism of trialkylamine-based PILS have been reported [Burrell et al., 2010; Blanchard et al., 2011]. PILS show a peculiar dynamic behaviour with similar values for cation and anions diffusion coefficients thus indicating that the ions are tightly bound together as ion pairs. Miran et al. [2012] studied the influence on the diffusion motion of different Brønsted acids with wide variations in the pKa. They found that the cation and anion diffusion coefficients are dependent on the structure and strength of the Brønsted acids. Anouoti et al. [2012] investigated the transport mechanisms of two pure IL [pyr][HSO4], [pyr][CF3COO] and their mixture with water. The diffusion of both ions was similar, while mobile protons attached to nitrogen atoms exhibited faster diffusion motion. These results indicate that proton conduction follows a combination of Grotthuss- and vehicle-type mechanisms. The same transport mechanism was found in [Im][Tf2N] system [Noda et al., 2003]. Hoarftrost et al. [2012] demonstrated that a proton hopping mechanism occurs when the IL [Im][Tf2N] contains imidazole in excess leading to enhanced conductivity over a wide temperature range (300-420) K.

Contents

4.1.2 IL mixtures The transport properties of IL binary and ternary mixtures sharing the same [C4C1pyr]+ cation and combining different anion have been studied by Castiglione et al. [2010]. The binary systems were [C4C1pyr ][Tf2N]-[C4C1pyr ][Pf2N], [C4C1pyr ][Tf2N]-[C4C1pyr ][IM14], [C4C1pyr ][Pf2N]-[C4C1pyr ][IM14]. The ternary mixture was obtained combining all three anions. For only one binary mixture [C4C1pyr][Tf2N]-[C4C1pyr][IM14] the anion diffusivity deviated from the predictable linear behaviour showing better performances. This is probably due to marked difference in size and fluorine content of the two anions leading to a formation of fluorine domains. Similarly, the IL mixture [Kunze et al., 2012] [C4C1pyr][Tf2N]-[C3C1pyr][FSI] showed excellent low temperature conductivity properties far exceeding those of the pure IL.

4.1.3 Solute molecules The IL properties are greatly affected by the presence of a solute. For instance, the addition of water into ILs [C2C1Im][EtSO4], [C2C1Im][TfO] [Menjoge et al., 2009] and [C2C1Im][MeSO3] [Stark et al., 2011], increases the diffusion coefficient of both cation and anion and decreases the difference between ions diffusion coefficients. These results indicate that water causes a gradual, continual break-up of the polar domains due to anion-water hydrogen bond formation. These findings are in agreement with MD simulations which observed a percolating network of water in IL when the molar portion of water reaches 0.75 [Hanke and Lynden-Bell, 2003]. Hydrogen-bonding interactions are also responsible of carbohydrate solvation in ILs systems. Several studies on the structure and dynamics of both cellulose and short oligomer models (cellobiose and glucose) in either imidazolium chloride or acetate-based IL [Remsing et al., 2008; Youngs et al., 2011] are reported. A decrease in the ion diffusion coefficients was found on dissolution of glucose compared with the pure ILs. This is explained with the increase of viscosity due to the strong hydrogen-bonding interactions between the sugar hydroxyl groups and the IL anion. NOESY experiments lend further evidence of no direct interaction between the sugar and acidic hydrogens of the cation. Some authors, however, suggested that the heterocyclic cation plays an important role due to its ability to associate

Bibliography

with oxygen atoms of hydroxyls [Zhang et al., 2010]. Recently, Ries et al. [2014] analyzed the ion diffusion coefficients of the pure [C2C1Im][OAc] and in solution with (glucose/cellobiose/cellulose) for a range of concentrations (0−15% w/w) of each carbohydrate. The authors found that the molar ratio of carbohydrate OH groups to ionic liquid molecules, α, is the key parameter in determining the diffusion coefficients of the IL ions.Ionic interactions between anionic PAMAM dendrimer and IL systems have been observed by Zhao et al. [2012] NOE and PGSE experiments were performed in order to determine any correlations between PAMAM dendrimers and three alkylimidazolium-based IL as a function of IL/dendrimer molar ratio. A decreased diffusion coefficient for the IL cation in the IL-anionic dendrimer solution showed the presence of weak ionic interactions, while no inclusion complexes are formed at different pH conditions. Moreover, small molecules have been dissolved in ILs at low concentration. The tracer diffusion of several aromatic solutes of moderate size dissolved in the series [CnC1pyr] [Tf2N] n=3,4,6,8,10 was reported by Kaintz et al. [2013]. The authors studied the effects of specific solute properties such as size, shape and solute charge responsible of ionic interactions observing the solute diffusion coefficient. A comparison with conventional solvents showed quite similar trends.Due to recent application of IL for gas separation and/or storage, the diffusivity of carbon dioxide in [C4C1Im][Tf2N] has been investigated [Hazelbaker et al., 2012] by 13C PGSE NMR and MD simulations for a broad range of temperature and CO2 content. Addition of CO2 into the ionic liquid increases the ion diffusivities. Under the examined conditions, the diffusion coefficients of carbon dioxide were found to be approximately an order of magnitude larger than the corresponding diffusivity of the IL ions. Hence DCO2 > Dcation >Danion. MD simulations showed that CO2 occupies cavities within the ionic liquid, resulting in a small change of the total volume. Hazelbaker et al. [2015] also found an increased CO2 diffusivity for a mixture of IL/CO2 confined in a mesoporous material (KIT-6 silica).

4.2 Rotational motion

Contents

Field-Cycling (FC-NMR) relaxometry [Kimmich and Annoardo, 2004] is based on relaxation measurements at different values of magnetic field. Although this is a powerful method for method for the study of all the dynamic processes, only few applications for ILs are reported, and mainly concerning magnetic ionic liquids (MILs) [Daniel et al., 2013] . Neves et al. [2011] investigated the IL cations mobility and the confinement within modified Nafion/IL membranes for three ILs systems. Among the three studied systems, the [C6H5N(C1)3]+ cation imposes a more confined and structured dynamic, when compared with Nafion/[C4C1Im]+ and Nafion/[C12(C1)3N]+ membranes. Alternatively high resolution technique at a fixed frequency based on the inversion recovery and Carr-Purcell-Meiboom-Gill (CPMG) pulse sequences have been extensively used. Although ILs are liquids, due to their high viscosity, some nuclei (1H, 7Li) show a T1 minimum in the Arrhenius plots, consequently the classical Bloembergen, Purcell and Pound (BPP) theory [Traficante, 1996] can be applied to obtain the rotational correlation time c for the motion of dipoles within a molecule. Using the BPP model Imanari et al. [2008, 2010, 2012] discussed the reorientational dynamics and the phase behaviour of [CnC1Im][Br] (n=1,2,3,4) in the 203-393 K temperature range. The existence of liquid, super-cooled state and coagulated state in the cooling process was shown by 1H and 13C relaxation times. The values of 1H-T1 and 13C-T1, determined for each site of the molecule, suggest that some carbons continue to move even in the crystalline and/or solid states. The effects in the rotational dynamics induced by the imidazolium ring -C(2) methylation in [C1C4C1Im]Br was studied by Endo et al. [2011, 2012]. They also investigated the cation and anion phase behaviour of [C1C2Im][PF6] using the T1 and T2 relaxation times of 13C, 31P and 19F. The authors found that anions dynamic is dominated by free rotational diffusion at temperatures above 230 K, while a restricted rotational or librational motion dominates at lower temperatures. Alam et al. [2011] used a quadrupolar nucleus, 14N, to follow the relaxation behaviour (T1 and T2) as a function of temperature (Figure 1.4) for a series of tetra-alkyl acyclic ammonium and cyclic pyrrolidinium ionic liquids (ILs). The correlation times c for the molecular reorientation and motion of the nitrogen substituents (N-C bond rotations) were directly evaluated from the ratio

Bibliography

T2/T1 and the values are in the range 2-14 ns. Shorter c values are reported for imidazolium ILs [Carper et al., 2004]. Similar studies were performed for [C3C1 C1Im][Tf2N] [Hayamitzu et al., 2008], [C4C1pip][Tf2N] [Han et al., 2012] and [C4C1pyr][Tf2N] [Guo et al., 2012]. In all systems slow internal N-CH3 rotation rates were observed (NCH3 10-100 ps) for several hard and soft anions. The long correlation times observed for N-CH3 rotation is a general property of the local cation structure. The relationship between translational and rotational motions has been investigated by combining T1 measurements and PFGSE experiments. Hayamitzu et al. [2012, 2011, 2010] reported a multinuclear (1H, 11B, 19F) study of [C2C1Im][BF4] and [C4C1Im][BF4] down to about 250 K. The relationship between the diffusion coefficient D and the correlation times c (1H) cation, c (19F) - c (11B) anion, indicate that the two type of motion are strongly coupled. The effects of a lithium salt on the ILs motion has been reported for [C3C1pyr][Tf2N]-Li[Tf2N], [C3C1pyr][Tf2N]-Li[Tf2N] and for [DEME][Tf2N]-Li[Tf2N] mixtures. In the latter case, c(Li) is longer than c(H), suggesting that the molecular motion of the cations occurs more rapidly than the lithium jump. Umecky et al. [2013] studied the effect of water dissolved into [C2C1Im][Tf2N] on the solvation structure and dynamics of Li+. The mean one-jump distances of Li+ RLi in the IL-water solutions were estimated from the correlation times c(Li) and the self-diffusion coefficients. RLi decreased to 0.25 nm with increasing the molar ratio [H2O]/[Li] up to 6. Moreover, Endo et al. [2015] used 81Br NMR to measure T1 and T2 of two ILs, [C4C1Im][Br] and [C4C1mim]Br. The correlation time τc(Br) as well as the quadrupolar constant constant CQ were determined. The CQ values, of [C4C1Im][Br] and [C4C1mim][Br] in the crystalline state are estimated to be around 6.22 and 6.52 MHz, respectively and is reduced by nearly 50% in the liquid state. The CQ can be correlated with the distance between the cation–anion.

5. ConclusionsThe recent literature shows the continuous experimental and theoretical work towards a detailed structural description of tremendously complex systems such as ILs, their blends and the solutions of ILs. Since the formulation of the concept of “nanostructured organization” of ILs

Contents

[Canongia Lopes and Pádua, 2006] and the first experimental proof of the formation of nanosegregated domains within the pure ILs [Triolo et al., 2007], many efforts has been oriented in the direction of a deeper understanding of the local order in ILs. In this scenario, the NMR methods briefly and non-exhaustively outlined in this chapter do provide a precious contribution to the definition of the mosaic, especially when inserted in a multidisciplinary approach, which, at moment, represents the most important research perspective [Marake et al., 2015; Russina et al., 2013]. Indeed, the modern research exploits NMR methods in the same toolbox of other powerful structural methods such as x-ray and neutron scattering, vibrational spectroscopies, electrochemical techniques and quantum chemical methods.

Bibliography

Alam, T. M., Dreyer, D. R., Bielwaski, C. W., and Ruoff, R. S. (2011). Measuring Molecular Dynamics and Activation Energies for Quaternary Acyclic Ammonium and Cyclic Pyrrolidinium Ionic Liquids Using 14N NMR Spectroscopy, J. Phys. Chem. A, 115, pp. 4307-4316.

Anouti, M., Porion, P., Brigouleix, C., Galiano, H., and Lemordant, D. (2010). Transport properties in two pyrrolidinium-based protic ionic liquids as determined by conductivity, viscosity and NMR self-diffusion measurements, Fluid Phase Equilib., 299, pp. 229-237.

Anouti, M., Jacquemin J., and Porion, P. (2012). Transport Properties Investigation of Aqueous Protic Ionic Liquid Solutions through Conductivity , Viscosity , and NMR Self-Diffusion Measurements, J. Phys. Chem. B., 116, 4228-4238.

Araujo, J. M. M., Ferreira, R., Marrucho, I. M., and Rebelo, L. P. N. (2011). Solvation of Nucleobases in 1,3-Dialkylimidazolium Acetate Ionic Liquids: NMR Spectroscopy Insights into the Dissolution Mechanism, J. Phys. Chem. B, 115 pp. 10739-10749.

Araujo, J. M. M., Pereiro, A. B., Canongia Lopes, J. N., Rebelo, L. P. N., Marrucho, I. M. (2013). Hydrogen-Bonding and the Dissolution Mechanism of Uracil in an Acetate Ionic Liquid: New Insights from NMR Spectroscopy and Quantum Chemical Calculations, J. Phys. Chem. B, 117, 4109-4120.

Bagno, A., Rastrelli, F., and Saielli, G. (2005). NMR techniques for the investigation of solvation phenomena and non-covalent interactions, Prog. Nucl. Magn. Reson. Spectrosc., 47 pp. 41-93.

Bagno, A., D’ Amico, F., and Saielli, G. (2006). Computing the NMR Spectrum of a Bulk Ionic Liquid Phase by QM/MM Methods, J. Phys. Chem. B, 110, pp. 23004-23006.

Balevicius, V., Gdaniec, Z., Aidas, K., and Tamuliene, J. (2010). NMR and Quantum Chemistry Study of Mesoscopic Effects in Ionic Liquids, J. Phys. Chem. A, 114, 5365-5371.

Bankmann, D. and Giernoth, R. (2007). Magnetic resonance spectroscopy in ionic liquids, Prog. Nucl. Magn. Reson. Spectrosc., 51 pp. 63-90.

17

18 Bibliography

Blanchard, J. W., Beli, J., Alam, T. M., Yarger, L. and Holland, G. P., (2011). NMR Determination of the Diffusion Mechanisms in Triethylamine-Based Protic Ionic Liquids, Phys. Chem. Lett., 2, pp. 1077-1081.

Bogle, X., Vazquez, R., Greenbaum, S., von Wald Cresce, A., Xu, K. (2013). Understanding Li+-Solvent Interaction in Nonaqueous Carbonate Electrolytes with 17O NMR, J. Phys. Chem. Letters, 4, pp. 1664-1668.

Bohmer, R., Jeffrey, K.R., Vogel, M. (2007). Solid-state Li NMR with applications to the translational dynamics in ion conductors, Prog. Nucl. Magn. Reson. Spectrosc., 50, pp. 87-174.

Borodin, O., Gorecki, W., Smith, G. D., Armand, M. (2010). Molecular Dynamics Simulation and Pulsed-Field Gradient NMR Studies of Bis(fluorosulfonyl)imide (FSI) and Bis[(trifluoromethyl)sulfonyl]imide (TFSI)-Based Ionic Liquids., J. Phys. Chem. B, 114, pp. 6786-6798.

Brand, T., Cabrita, E. J., Berger, S. (2005). Intermolecular interaction as investigated by NOE and diffusion studies., Prog. Nucl. Magn. Reson. Spectrosc., 46, pp. 159-196.

Burrell, G., L., Burgar, I. M., Gong, Q., Dunlop, N. F., and Separovic, F. (2010). NMR relaxation and self-diffusion study at high and low magnetic fields of ionic association in protic ionic liquids., J. Phys. Chem. B, 114, pp. 11436-11443.

Burrell, G. L., Burgar, I. M., Separovic, F., and Dunlop, N. F. (2010) Preparation of protic ionic liquids with minimal water content and (15)N NMR study of proton transfer., Phys. Chem. Chem. Phys., 12, pp. 1571-1577.

Canongia Lopes, L. N. A. and Pádua, A. A. H. (2006). Nanostructural Organization in Ionic Liquids. J. Phys. Chem. B, 110, pp. 3330-3335.

Carper, W. R., Wahlbeck, P. G., and Dolle, A. (2004). 13C NMR Relaxation Rates: Separation of Dipolar and Chemical Shift Anisotropy Effects, J. Phys. Chem. A, 108, pp. 6096-6099.

Castiglione, F., Raos, G., Appetecchi, G. B., Montanino, M., Passerini, S., Moreno, M., Famulari, A., and Mele, A. (2010). Blending ionic liquids: how physico-chemical properties change? Phys Chem Chem Phys, 12 pp. 1784-1792.

Castiglione, F., Ragg, E., Mele, A., Appetecchi, G. B., Montanino, M., and Passerini|, S. (2011). Molecular Environment and Enhanced Diffusivity of Li+ Ions in Lithium-Salt-Doped Ionic Liquid Electrolytes, J. Phys. Chem. Lett., 2, pp. 153-157.

Castiglione, F., Simonutti, R., Mauri, M., and Mele, A. (2013). Cage-Like Local Structure of Ionic Liquids Revealed by a 129Xe Chemical Shift, J. Phys. Chem. Lett., 4, pp. 1608-1612.

Castiglione, F., Famulari, A., Raos, G., Meille, S. V., Mele, A., Appetecchi, G. B., and Passerini, S. (2014). Pyrrolidinium-Based Ionic Liquids Doped with Lithium Salts: How Does Li+ Coordination Affect Its Diffusivity?, J. Phys. Chem. B, 118, pp. 133679-133688.

Castiglione, F., Appetecchi, G.B., Passerini, S., Panzeri, W., Indelicato, S., Mele, A. (2015). Multiple points of view of heteronuclear NOE: Long range vs short range

Bibliography

contacts in pyrrolidinium based ionic liquids in the presence of Li salts, J. Mol. Liq., 210, pp. 215-222.

Chen, S., Douglas V., MacFarlane, R., and Izgorodina, E. I. (2013). Ab Initio Prediction of Proton NMR Chemical Shifts in Imidazolium Ionic Liquids, J. Phys. Chem. B, 117, pp. 3186-3197.

Chen, Y.; Cao, Y.; Sun, X.; Mu, T. (2014). Hydrogen Bond Interaction Between Acetate-Based Ionic Liquid 1-Ethyl-3-Methylimidazolium Acetate and Common Solvents, J. Mol. Liq., 190, 151-158.

Cremer, T., Kolbeck, C., Lovelock, K. R. J., Paape, N., Wölfel, R., Schulz, P. S., Wasserscheid, P., Weber, H., Thar, J., Kirchner, B., Maier, F., and Steinrück, H.-P. (2010). Towards a molecular understanding of cation-anion interactions--probing the electronic structure of imidazolium ionic liquids by NMR spectroscopy, X-ray photoelectron spectroscopy and theoretical calculations., Chem. Eur. J., 16, pp. 9018 – 9033.

Daniel,C. I., Chávez, F. V., Feio, G., Portugal,C. A. M., Crespo,J. G., and Sebastiao, P. J. (2013). 1H NMR Relaxometry, Viscometry, and PFG NMR Studies of Magnetic and Nonmagnetic Ionic Liquids, J. Phys. Chem. B, 117, pp 11877-11884.

Endo, T., Imanari, M., Seki, H., Nishikawa, K. (2011). Effects of Methylation at Position 2 of Cation Ring on Rotational Dynamics of Imidazolium-Based Ionic Liquids Investigated by NMR Spectroscopy: [C4mim]Br vs [C4C1mim]Br, J. Phys. Chem. A 115, pp. 2999-3005.

Endo, T., Widgeon, S., Yu, P., Sen, S., Nishikawa, K. (2012). Cation and anion dynamics in supercooled and glassy states of the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate: Results from 13C, 31P, and 19F NMR spectroscopy, Phys. Rev. B, 85, 054307-1-9.

Endo, T., Imanari, M., Hidaka, Y., Seki, H., Nishikawa, K., and Send, S. (2015). Structure and dynamics of room temperature ionic liquids with bromide anion: results from 81Br NMR spectroscopy, Magn. Reson. Chem., 53, pp. 369–378.

Falcone, R. D., Baruah, B., Gaidamauskas, E., Rithner, C. D., Correa, N. M., Silber, J. J., Crans, D. C., and Levinger, N. E. (2011). Layered structure of room-temperature ionic liquids in microemulsions by multinuclear NMR spectroscopic studies., Chem. Eur. J., 17, pp. 6837–6846.

Gabl, S., Steinhauser, O., Weingärtner, H. (2013). From Short-Range to Long-Range Intermolecular NOEs in Ionic Liquids: Frequency Does Matter, Angew. Chem. Int. Ed., 52, pp. 9242-9247.

Gericke, M., Fardim, P., Heinze, T. (2012). Ionic Liquids Promising but Challenging Solvents for Homogeneous Derivatization of Cellulose, Molecules, 17, pp. 7458-7502.

Giernoth, R. (2010) Task Specific Ionic Liquids, Angew. Chem. Int. Ed., 49, pp. 654-670.

Greaves, T. L. and Drummond, C. J. (2008). Protic Ionic Liquids: Properties and Applications, Chem. Rev. 108, pp. 206-237.

20 Bibliography

Guo, J., Han,K. S., Mahurin,S. M., Baker, G. A., Hillesheim, P. C., Dai, S., Hagaman, E. W., and Shaw R. W. (2012). Rotational and Translational Dynamics of Rhodamine 6G in a Pyrrolidinium Ionic Liquid: A Combined Time-Resolved Fluorescence Anisotropy Decay and NMR Study, J. Phys. Chem. B, 116, pp 7883-7890.

Gutel, T., Santini, C. C., Pa, A. H., Fenet, B., Chauvin, Y., Gomes, M. F. C., and Pensado, A. S. (2009). Interaction between the π -System of Toluene and the Imidazolium Ring of Ionic Liquids : A Combined NMR and Molecular Simulation Study, J. Phys. Chem. B, 113, pp. 170–177.

Hallett, J. P and Welton, T. (2011). Room-Temperature Ionic Liquids: Solvents for Synthesis and Catalysis. 2, Chem. Rev. 111, 3508-3576.

Han, K. S., Li, S., Hagaman, E. W., Baker, G. A., Cummings, P., and Dai, S. (2012). Rotational and Translational Dynamics of N-Butyl-N-methylpiperidinium Trifluoromethanesulfonimide Ionic Liquids Studied by NMR and MD Simulations, Phys. Rev. C, 116, pp. 20779-20786.

Hanke, C. G., Lynden-Bell, R.M. (2003). A Simulation Study of Water-Dialkylimidazolium Ionic Liquid Mixtures, J. Phys. Chem. B, 107, pp. 10873–10878.

Hazelbaker, E. D., Budhathoki, S., Katihar, A., Shah, J. K., Maginn, E. J., and Vasenkov, S. (2012). Combined Application of High-Field Diffusion NMR and Molecular Dynamics Simulations To Study Dynamics in a Mixture of Carbon Dioxide and an Imidazolium-Based Ionic Liquid, J. Phys. Chem. B, 116, pp 9141-9151.

Hazelbaker, E. D., Guillet-Nicolas, R., Thommes, M., Kleitz, S., and Vasenkov, S. (2015). Influence of confinement in mesoporous silica on diffusion of a mixture of carbon dioxide and an imidazolium-based ionic liquid by high field diffusion NMR, Microporous Mesoporous Mater., 206, pp. 177–183.

Hayamizu, K., Tsuzuki, S., Seki, S., Umebayashi, Y. (2012). Multinuclear NMR studies on translational and rotational motion for two ionic liquids composed of BF 4 anion, J. Phys. Chem. B, 116, pp11284–11291.

Hayamizu, K., Tsuzuki, S., Seki, S., Ohno, Y., Miyashiro, H., and Kobayashi, Y. (2008). Quaternary Ammonium Room-Temperature Ionic Liquid Including an Oxygen Atom in Side Chain/Lithium Salt Binary Electrolytes: Ionic Conductivity and 1H, 7Li, and 19F NMR Studies on Diffusion Coefficients and Local Motions, J. Phys. Chem. B, 112, pp. 1189–1197.

Hayamizu, K.; Tsuzuki, S.; Seki, S.; Umebayashi, Y. (2011). Nuclear Magnetic Resonance Studies on the Rotational and Translational Motions of Ionic Liquids composed of 1-Ethyl-3-methylimidazolium Cation and Bis(trifluoromethanesulfonyl)amide and Bis-(fluorosulfonyl)amide Anions and their Binary Systems including Lithium Salts. J. Chem. Phys., 135, 84505-84511.

Hayamizu, K.; Tsuzuki, S.; Seki, S.; Fujii, K.; Suenaga, M.; Umebayashi, Y. (2010). Studies on the Translational and Rotational Motions of Ionic Liquids composed of

Bibliography

N-methyl-N-propyl-pyrrolidinium (P13) Cation and Bis(trifluoromethanesulfonyl)amide and Bis-(fluorosulfonyl)amide Anions and their Binary Systems including Lithium Salts. J. Chem. Phys., 133, pp. 194505-194513.

Hayamizu, K., Tsuzuki, S., and Seki, S. (2008). Molecular Motions and Ion Diffusions of the Room-Temperature Ionic Liquid 1 , 2-Dimethyl-3-propylimidazolium Bis ( trifluoromethylsulfonyl ) amide ( DMPImTFSA ) Studied by 1H , 13C , and 19F NMR, J. Phys. Chem. A, pp. 12027–12036.

Herriot., C., Khatun, S., Fox, E. T., Judeinstein, P., Armand, M., Henderson, W. A., and Greenbaum, S. (2012). Diffusion Coefficients from 13C PGSE NMR Measurements -Fluorine- Free Ionic Liquids with the DCTA - Anion, J. Phys. Chem. Lett., 3, pp. 3–6.

Hoarfrost, M. L., Tyagi, M., Segalman, R. A., and Reimer, J. A. (2012). Proton hopping and long-range transport in the protic ionic liquid [Im][TFSI], probed by pulsed-field gradient NMR and quasi-elastic neutron scattering., J. Phys. Chem. B, 116, pp. 8201–8209.

Holbrey, J. D. and Rogers, R. D. (2008) Physicochemical Properties of Ionic Liquids: Melting Points and Phase Diagrams, in Ionic Liquids in Synthesis, 2nd Edition, Wasserscheid P. and Welton, T. Eds. WILEY-VCH Weinheim, pp. 57-72.

Kaintz, A., Baker, G., Benesi, A., and Maroncelli, M. (2013). Solute Diffusion in Ionic Liquids , NMR Measurements and Comparisons to Conventional Solvents, J. Phys. Chem. B, 117, pp. 11697–11708.

Khatun S., and Castner, E. W. Jr. (2015). Ionic Liquid-Solute Interactions Studied by 2D NOE NMR Spectroscopy, J. Phys. Chem. B, 119, pp. 9225-9235.

Kimmich R, Annoardo E. (2004). Field-cycling NMR relaxometry, Prog. Nucl. Magn. Reson. Spectrosc., 44, pp 257–320.

Kunze, M., Jeonga, S., Appetecchi, G. B., Schönhoffb, M., Wintera, M., Passerinia, S. (2012). Mixtures of ionic liquids for low temperature electrolytes, Electrochim. Acta, 82, pp. 69-74.

Kuroda, K., Kunimura, H., Fukaya, Y., and Ohno, H. (2014). 1H NMR analysis of cellulose dissolved in non-deuterated ionic liquids, Cellulose, 21, pp. 2199-2206.

Imanari, M., Nakakoshi, M., Seki, H., and Nishikawa, K. (2008). 1H NMR study on reorientational dynamics of an ionic liquid, 1-butyl-3-methylimidazolium bromide, accompanied with phase transitions, Chem. Phys. Lett., 459, pp. 89–93.

Imanari, M., Tsuchiya, H., Seki, H., Nishikawa, K., and Tashiro, M. (2009). Characterization of the molecular reorientational dynamics of the neat ionic liquid 1-butyl-3-methylimidazolium bromide in the super cooled state using 1H and 13C NMR spectroscopy, Magn. Reson. Chem., 47, pp. 67-70.

Imanari M, Uchida K, Miyano K, Seki H, Nishikawa K. (2010). NMR study on relationships between reorientational dynamics and phase behaviour of room-temperature ionic liquids: 1-alkyl-3-methylimidazolium cations, Phys. Chem. Chem. Phys., 12 pp 2959-2967.

22 Bibliography

Imanari M, Fujii K, Endo T, Seki H, Tozaki K, Nishikawa K. (2012). Ultraslow Dynamics at Crystallization of a Room-Temperature Ionic Liquid, 1-Butyl-3-methylimidazolium Bromide, J. Phys. Chem. B, 116, pp 3991-3997.

Joshi, R., Pasilis, S. P. (2015). The effect of tributylphosphate and tributyl phosphine oxide on hydrogen bonding interactions between water and the 1-ethyl-3-methylimidazolium cation in 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, J. Mol. Liq., 209, pp. 381-386.

Judeinstein, P., Iojoiu, C., Sanchez, J.-Y., Ancian, B., (2008). Proton Conducting Ionic Liquid Organization as Probed by NMR : Self-Diffusion Coefficients and Heteronuclear Correlations, J. Phys. Chem. B, 112, pp. 3680–3683.

Lee, H. Y.; Shirota, H.; Castner, E. W., Jr. (2013). Differences in Ion Interactions for Isoelectronic Ionic Liquid Homologs, J. Phys. Chem. Lett., 4, pp. 1477-1483.

Lingscheid, Y.; Arenz, S.; Giernoth, R. (2012). Heteronuclear NOE Spectroscopy of Ionic Liquids, Chem. Phys. Chem., 13, pp. 261-266.

Lycka, A., Dolecek, R., Simunek, P., and Machacek, V. (2006). 15N NMR spectra of some ionic liquids based on 1,3-disubstituted imidazolium cations, Magn. Reson. Chem., 44, pp. 521–523.

Marekha, B. A., Kalugin, O. N., Bria, M., and Idrissi, A. (2015). Probing structural patterns of ion association and solvation in mixtures of imidazolium ionic liquids with acetonitrile by means of relative (1)H and (13)C NMR chemical shifts, Phys. Chem. Chem. Phys., 17, pp. 23183–23194.

Marekha, B. A., Bria, M., Moreau, M., DeWaele, I., Miannay, F. A., Smortsova, Y., Takamuku, T., Kaluginc, O. N., Kiselev, M., Idrissi, A. (2015). Intermolecular interactions in mixtures of 1-n-butyl-3-methylimidazolium acetate and water: Insights from IR, Raman, NMR spectroscopy and quantum chemistry calculations, Intermolecular interactions in mixtures of 1-n-butyl-3-methylimidazolium acetate and water: Insights from IR, Raman, NMR spectroscopy and quantum chemistry calculations, J. Mol. Liq., 210, pp.217-227.

Marincola, F. C., Piras, C., Russina, O., Gontrani, L., Saba, G., Lai, A. (2012). NMR Investigation of Imidazolium-Based Ionic Liquids and Their Aqueous Mixtures, Chem Phys Chem, 13, pp. 1339-1346.

Mele, A. (2010). NOE experiments for ionic liquids. Tools and strategies. Chim. Oggi/Chem. Today 28, pp. 48-55.

Menjoge, A., Dixon, J., Brennecke, J F., Maginn, E. J., and Vasenkov, S. (2009). Influence of water on diffusion in imidazolium-based ionic liquids: a pulsed field gradient NMR study, J. Phys. Chem. B,113, pp. 6353–6359.

Miran, M., Kinoshita, H.,Yasuda, T., Susan, A. B. H., and Watanabe, M. (2012). Physicochemical properties determined by pKa for protic ionic liquids, Phys Chem Chem Phys, 14 pp 5178-5186.

Morgado, P., Shimizu, K., Esperanca, J. M. S. S., Reis, P. M., Rebelo, L. P. N., Canongia Lopes, J. N., and Filipe, E. J. (2013). Using 129Xe NMR to probe the structure of ionic liquids, J. Phys. Chem. Lett., 4, pp. 2758–2762.

Bibliography

Mustarelli, P. (2010). The Development of High Temperature PEMFCs: Reasonsand Perspectives, Fuel Cells,10, pp. 753-753.

Neuhaus, D. and Williamson, M. P. (2000) The Nuclear Overhauser Effect in Structural and Conformational Analysis, 2nd Edition. Wiley, New York.

Neves, L. A., Sebastiao, P. J., Coelhoso,I. M., and Crespo J. G. (2011). Proton NMR Relaxometry Study of Nafion Membranes Modified with Ionic Liquid Cations, J. Phys. Chem. B, 115, pp 8713-8723.

Nockemann, P., Thijs B., Lunstroot K., Parac-Vogt T.N., Gorller-Walrand C., Binnemans K. (2009). Speciation of Rare-Earth Metal Complexes in Ionic Liquids: A Multiple-Technique Approach, Chem Eur J, 15, pp. 1449-1461.

Noda, A., Susan, A. B. H., Kudo, K., Mitsushima,S., Hayamizu, K., and Watanabe, M. (2003). Brønsted Acid-Base Ionic Liquids as Proton-Conducting Nonaqueous Electrolytes, J. Phys. Chem. B, 107, pp. 4024-4033.

Pal, A., and Kumar, B. (2012). Densities, speeds of sound and 1H NMR spectroscopic studies for binary mixtures of 1-hexyl-3-methylimidazolium based ionic liquids with ethylene glycol monomethyl ether at temperature from T=(288.15–318.15) K, Fluid Phase Equilib., 334, pp. 157–165.

Pal, A., and Kumar, B. (2011). Volumetric, acoustic and spectroscopic studies for binary mixtures of ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate) with alkoxyalkanols at T = (288.15 to 318.15) K, J . Mol. Liq., 163, pp. 128–134.

Puttick, S., Davis, A. L., Butler, K., Lambert, L., El harfi, J., Irvine, D. J., Whittaker, A. K., Thurecht, K. J., Licence, P. (2011). NMR as a probe of nanostructured domains in ionic liquids: Does domain segregation explain increased performance of free radical polymerisation? Chem. Sci., 2, 1810-1816.

Radhi, A., Le, K. A., Ries, M. E., and Budtova, T. (2015). Macroscopic and Microscopic Study of 1-Ethyl-3-methyl-imidazolium Acetate-DMSO Mixtures, J. Phys. Chem. B, 119, pp. 1633–1640.

Remsing, R. C. Hernandez, G., Swatloski, R. P., Massefski, W. W., Rogers, R. D., and Moyna, G. (2008). Solvation of Carbohydrates in N , N ′ -Dialkylimidazolium Ionic Liquids : A Multinuclear NMR Spectroscopy Study, J. Phys. Chem. B, 112, pp. 11071–11078.

Remsing, R. C., Liu, Z., Sergeyev, I., and Moyna, G. (2008). Solvation and Aggregation of N , N ′ -Dialkylimidazolium Ionic Liquids: A Multinuclear NMR Spectroscopy and Molecular Dynamics Simulation Study, J. Phys. Chem. B, 112, pp. 7363–7369.

Ries, E. R., Radhi, A., Keating, A. S., Parker,O., Budtova, T. (2014). Diffusion of 1-Ethyl-3-methyl-imidazolium Acetate in Glucose, Cellobiose, and Cellulose Solutions, Biomacromolecules, 15, pp. 609-617.

Rollet, A.-L., Bessada, C. (2013). NMR Studies of Molten Salt and Room Temperature Ionic Liquids, Annual Reports on NMR Spectroscopy, 78, pp. 149–207.

24 Bibliography

Ruiz, E., Ferro, V. R., Palomar, J., Ortega, J., and Rodriguez, J. J. (2013). Interactions of ionic liquids and acetone: thermodynamic properties, quantum-chemical calculations, and NMR analysis., J. Phys. Chem. B, 117, pp. 7388–7398.

Russina, O., Lo Celso, F., Di Michiel, M., Passerini, S., Appetecchi, G. B., Castiglione, F., Mele, A., Caminiti, R., and Triolo, A. (2013). Mesoscopic structural organization in triphilic room temperature ionic liquids, Faraday Discuss. 167, 499-513.

Saielli, G., Bagno, A., Castiglione, F., Simonutti, R., Mauri, M., and Mele, A. (2014). Understanding Cage Effects in Imidazolium Ionic Liquids by 129Xe NMR: MD Simulations and Relativistic DFT Calculations, J. Phys. Chem. B, 118, pp. 13963-13968.

Sangoro, J. R., Iacob, C., Naumov, S. Valiullin, R., Rexhausen, H., Hunger, J., Buchner, R., Strehmel, V., Karger, J., and F. Kremer (2011). Diffusion in ionic liquids: the interplay between molecular structure and dynamics, Soft Matter, 7, pp. 1678-1681.

Seitkalieva, M. M., Grachev, A. A., Egorova, K. S., and Ananikov, V. P. (2014). Nanoscale organization of ionic liquids and their interaction with peptides probed by 13C NMR spectroscopy, Tetrahedron, 70, pp. 6075–6081.

Shimomura, T., Takamuku,T., and Yamaguchi, T. (2011). Clusters of Imidazolium-Based Ionic Liquid in Benzene Solutions, J. Phys. Chem. B, 115, pp. 8518–8527.

Shimomura, T., Inoue, S. Kadohata, S., Umecky, T., and Takamuku T. (2013). SANS, ATR-IR, and 1D- and 2D-NMR studies of mixing states of imidazolium-based ionic liquid and aryl solvents., Phys. Chem. Chem. Phys., 15, pp. 20565–20576.

Singh, T., Kumar, A. (2008). Fluorescence Behavior and Specific Interactions of an Ionic Liquid in Ethylene Glycol Derivatives, J. Phys. Chem. B, 112, pp. 4079–4086.

Singh, T., Rao, K.S., Kumar, A. (2011). Polarity Behaviour and Specific Interactions of Imidazolium-Based Ionic Liquids in Ethylene Glycol, Chem. Phys. Chem., 12, pp. 836–845.

Stark, A., Zidell, A. W., Hoffmann, M. M. (2011). Is the ionic liquid 1-ethyl-3-methylimidazolium methanesulfonate [emim][MeSO3] capable of rigidly binding water?, J. Mol. Liq., 160, pp. 166-179.

Su, B.-M., Zhang S. and Zhang, Z. C. (2004). Structural Elucidation of Thiophene Interaction with Ionic Liquids by Multinuclear NMR Spectroscopy, J. Phys. Chem. B, 108, pp. 19510-19517.

Takamuku, T., Hoke, H., Idrissi, A., Marekha, B. A., Moreau, M., Honda Y., Umecky, T., Shimomura, T. (2014). Microscopic interactions of the imidazolium-based ionic liquid with molecular liquids depending on their electron-donicity, Phys. Chem. Chem. Phys., 16, pp. 23627-23638.

Traficante, D. D. (1996). Relaxation: An Introduction, in Encyclopedia of Nuclear Magnetic Resonance, ed. M. D. Grant and R. K. Harris (Wiley, New York), 6, pp. 3988.

Bibliography

Triolo, A., Russina, O., Bleif, H.-J., and Di Cola, E. (2007). Nanoscale Segregation in Room Temperature Ionic Liquids, J. Phys. Chem. B, 111, pp. 4641-4644.

Tripathi, N., Saha, S. (2014). Unraveling the heterogeneity in N butyl-N-methylpiperidinium trifluromethanesulfonimide ionic liquid by 1D and 2D NMR spectroscopy, Chem. Phys. Lett., 607, pp. 57-63.

Tsuziki, S.; Hayamizu, K.; Seki, S. (2010). Origin of the Low-Viscosity of [emim][(FSO2)2N] Ionic Liquid and Its Lithium Salt Mixture: Experimental and Theoretical Study of Self-Diffusion Coefficients, Conductivities, and Intermolecular Interactions, J. Phys. Chem. B, 114, pp. 16329-16336.

Umecki, T., Saito, Y., Matsumoto, H. (2009). Direct Measurements of Ionic Mobility of Ionic Liquids Using the Electric Field Applying Pulsed Gradient Spin-Echo NMR. J. Phys. Chem. B, 113, pp. 8466-8468.

Umecky, T., Takamuku, T., Matsumoto, T., Kawai, E., Takagi, M., and Funazukuri, T. (2013). Effects of Dissolved Water on Li+ Solvation in 1-Ethyl-3-methylimidazolium Bis(trifluoromethanesulfonyl)amide Ionic Liquid Studied by NMR, J. Phys. Chem. B, 117, pp. 16219-16226.

Weingärtner, H. (2008) Understanding Ionic Liquids at the Molecular Level: Facts, Problems, and Controversies, Angew. Chem. Int. Ed., 47, 654-670.

Weingärtner, H., Cabrele, C., Herrmann, C. (2012). How ionic liquids can help to stabilize native proteins, Phys Chem Chem Phys, 14, pp. 415-426.

Weingärtner, H. (2013). NMR studies of ionic liquids: Structure and dynamics, Curr. Opin. Colloid Interface Sci.,18, pp. 183-189.

Youngs, T. G. A., Holbrey, J. D., Mullan, C. L., Norman, S. E., Lagunas, M. C., D’Agostino, C., Mantle, M. D., Gladden, L. F., Bowron, D. T., and Hardacre, C. (2011). Neutron diffraction, NMR and molecular dynamics study of glucose dissolved in the ionic liquid 1-ethyl-3-methylimidazolium acetate, Chem. Sci., 2, pp. 1594-2011.

Zhai, C., Wang, J., Zhao, Y., Tang, J., and Wang, H. (2006). A NMR Study on the Interactions of 1-Alkyl-3-Methylimidazolium Ionic Liquids with Acetone, Z. Phys. Chem., 220, pp. 775-785.

Zhang, J., Zhang, H., Wu, J., Zhang, J., Hea, J., and Xiang, J. (2010). NMR spectroscopic studies of cellobiose solvation in EmimAc aimed to understand the dissolution mechanism of cellulose in ionic liquids, Phys. Chem. Chem. Phys., 12, pp. 1941-1947.

Zhao, Y., Gao, S., Wang, J., and Tang, J., (2008). Aggregation of Ionic Liquids [Cnmim] Br (n) 4 , 6 , 8 , 10 , 12) in D2O : A NMR Study,” J. Phys. Chem. B, 112, pp. 2031-2039.

Zhao, L., Li, C., Zhang, J., Wu, Q., Xu, T., and Cheng, Y. (2012). Interactions between Dendrimers and Ionic Liquids Revealed by Pulsed Field Gradient and Nuclear Overhauser Effect NMR Studies, J. Phys. Chem. B, 116, pp. 7203-7212.

26 Bibliography

Index

chapters, 3, 6equation, 8floats, 3

figures, 8, 9lists, 3Math Environments, 10

Corollary, 10Proof, 10

Theorem, 10parts, 3, 5references

Numbered references, 12Unnumbered references, 11

references, 3template, 3, 5